Fritzbox4040, Problem calibrating WIFI

Dear Forum Readers

When installing a new Fritzbox4040, there is a problem setting up the WIFI.

In another case, also a Fritzbox4040 (devicename FB4040-201) I have under "Interfaces" an entry "WIFI, br-WIFI", see picture.

How I created this entry at that time, I don't know anymore. But I would like to have the same setup in the new Fritzxox4040, which is to span a second subnet, just with different IP addresses.

The WIFI network contains WLAN0 and WLAN1, and both have the same IP address. And this is exactly how I would like to set it up in the new device. I have already tried a few things with the bridge settings, but the result is not the same and the WLAN accesses do not work.

The internet at the LAN Poret is working well.

How do I get this interface into the new box?